Valve.



' No. 859,441. v PATENTED JULY 9, 1907.

\ J. mwoon.

VALVE.

APPLICATION FILED APR. e. 1966.

I l 9 IUIIVIII PATENT OFFICE.

ilOHN ERWOOD, OF CHICAGO, ILLINOIS.

VALVE Specification of Letters Patent.

Patented July 9, 1907.

Application filed April 9, 1906.' Serial No. 310,625.

To all whom it may concern: 7

Be it known that 1, JOHN Enwoon, a citizen of the United States,residing at Chicago, in thy county of Cook and State oi Illinois, haveinvented new and usei'ul Improvements in Valves, of which the followingis a specification, reference being had to the accompanying drawings,forming a part thereof.

The purpose of this invention is to provide an improved blow-ofi valvefor steam boilers which shall be superior to any new in use in respectto freedom l'rom liability to obstruction by scale or other hardsubstance issuing from the boiler.

It consist; ol the ieatures'oi construction set out in the claims.

In the drawings :Figure 1 is an axial section at the line 1-1 on Fig. 3of a valve embodying my improvements, the valve being shown in closedposition. Fig. 2 is a similar section at the line 22 on Fig. 3 showingthe valve partly open. Fig. 3 is a plan view of the valve.

The valve body, A, has a lateral coupling connection, A, for inlet fromthe boiler. The barrel or main limb of the body is cylindricallychambered from the :upperend down to a point about half an inch belowthe lower side of the inlet passage, the chamber being interiorlythreaded, not only above and past the inlet aperture, but substantiallyto the lower end of said cylindrical portionthat is, for the half inch,more or less, below said lower side of the inlet. Below that point thechamber is reduced in diameter and threaded to receive an annular brassseat, B, which may be rendered secure by a set screw, 1), set in fromthe outside oi the body. The valve, 0, is cylindrical and ex- .teriorlythreaded for engaging the interior thread of the cylindrical chamber,which, being of full diameter .to the top, permits the valve to beentered at the top and screwed down into the chamber to closed position,.the stem, G being integral with the body of the valve and emergingthrough a cap-plate, D, secured by "bolts, (Z, (1, taking through lugs,D, on the cap-plate, :and A, on the upper end of the body. A simple form(of gland, E, is provided to retain the packing, E the glandbeingsecured by bolts, E E taking through lugs on the gland, and on theupper end of the boss, D constituting a stuffing box, formed on the topof the cap-plate, D. The valve, 0, may be interiorly chambered on theunder side, merely for lightening it; and at the lower end it receivesin annular grooves cut j'ior that purpose a lead gasket or packing, F,for seating on the seat, B, the gasket being wider than the brass"wseat, and the brass seat being higher than the recess into which it isscrewed in the body, so that the contact of metal to metal at seating islimited to the lead :above and the brass seat below.

The difilculty arising from scale or other hard particles from theboiler getting between the valve and seat of a blow-off device andpreventing the valve from being closed after blowing off, is chieflycaused by the fact that as the valve approaches its seat in closing, andthe orilice through which the discharge occurring is greatly narrowed,any piece of scale or other hard I substance entering into the narrowedorifice is liable to be caught bet ween the two proximate faces of valveand seat, the shape of the scale permitting it to enter but not to passthrough, or the advancing valve catching the scale in the instant of itspassing. In the latter case the valve may be backed up to release thescale, but in the meantime it may be jammed into a corner of the seatand retained, or the shape may prevent it from escaping; and in anyevent, when there is considerable scale the same thing may recur asoften as the valve is operated for closing, a different piece beingcaught each time. In the operation of the valve shown in theconstruction of the above-described Valve, it is designed to preventthis diificulty; for it will be observed that in closing the valve theinlet is completely shut otf,except to leakage past the thread,-whilethe valve is still a half inch, more or less, from its seat. Any pieceof scale that might be caught at the margin of the inlet under the lowerend of. the valve in the closing movement of the latter is in anentirely different situation from piece of scale which might, inordinary construction of valves, be

caught between the valve and seat, because it is in position to besheared off by the continued closing movement, instead of to be merelypinched tight between two binding surfaces; and if sheared off it has ahalf inch clear space-in which to escape before the valve reaches itsAny scale that may be carried by the water passingwhile the valve iswide open, and which might be lodged upon the seat at the side oppositethe inlet will be almost certain to be flushed off in the continuedoperation. If a piece of scale should become thus lodged and remainuntil the valve is operated for closing, the only obstructive effectwill be that the valve cannot perfectly reach its seat; but it will havecut off the inlet while it is yet half an inch away from its seat, andthe leakage past the thread is so slight that it will not cause a boilerto be drained of water in many hours, so that danger of the boilerdraining out in the night on account 01' leaking blowoff is avoided. Y

The thread is designed to be sufliciently loose so that there will be nodanger of its binding on account of: unequal expansion and contraction,but steam at least, and to some extent, water, may pass the thread, andwater of condensation will accumulate above the valve in the valvechamber between the upper end of the valve head and the cap, D, and willconstitute a water packing of the thread, but the water will be readilylore ed out past the thread when the valve is opened, and thus all finesilt which might be carried past the 4 operation, and the thread will bekept perfectly clear at the upper part. At the lower part it will beevident that the-thread will be at all times flushed clear in theoperation of the valve.

I claiin:

1. A blow-off valve comprising a cylindrically chambered body having alateral port and a smooth annular valve seat in a plane transverse'tothe axis of the cylindrical chamber at a considerable distance from thenearer side of the port, such chamber being interiorly threaded at thezone of the port.and for a considerable distance therepast in thedirection of the valve seat ;-a cylindrical valve I exteriorly threadedfor engaging said interior thread and adapted to be screwed into thechamber from the side of the port opposite the seat and to. seat endwiseon said annular seat, and adapted when screwed into the chamber past theport to obstruct said port at all positions of its rotary movement inthe thread;

2. A blow oif valve comprising a body having a cylindrical chamberprovided with a lateral port and a smooth annular valve seat in a planetransverse to the axis of the chamber at a considerable distancelongitudinally of the chamber from the proximate side of the lateralport and having an axial port opening through said annular valve seat,the. chamber being threaded from a point at the opposite side of thelateral port from the seat to a point a considerable distance beyond theother sideof said port; and a cylindrical valve exterior-1y threadedfor-engaging said interior thread and adapted to be screwed into thechamber from the side of the port opposite the seat and to seat endwiseon said annular seat and adapted when screwed into the chamber past theport to obstruct said port at all positions of its rotary movement inthe thread.

3. A blow-arr valve comprising-.1 cylindrically chambered body open atboth ends and having a lateral port, the

. chamber of the body being reduced in diameter at a considerabledistance longitudinally from the proximate side of the lateral port andhaving a smooth annular valve seat formed on the, shoulder produced bysuch reduction of diameter, said chamber being interiorly-threaded atthe ,zone of the lateral port and for a considerable distance there-pasttoward said annular seat; a cylindrical valve exterior-1y threaded forengaging said interior thread and adapted to be screwed into the chamberfrom the side ofthe port opposite the seat and to seat endwise on said'annular seat, and adapted when screwed into the chamber past the port toobstruct said port at all positions of its rotary movementin'the thread.a

4. A valve body having a cylindrical chamber with a lateral port and anend port; a smooth annular valve seat which encompasses the end portlocated at a considerable distance longitudinally of the chamber fromthe proximate side of the lateral port, said chamber being threadedinteriorly at the zone of the lateral port and for a distance there-pastin both directions; a cylindrical valve exteriorly threaded for engagingsaid interior thread and adapted to be screwed into the chamber from theside of the port opposite the seat and to seat endwise on said annularseat, and adapted when screwed into the chamber past the port toobstruct said port at all positions of its rotary movement in thethread.

In testimony whereof, I have hereunto set my hand, in the presence oftwo witnesses, at Chicago, Illinois, this 7th day of April,- 1906.

JOHN ERWOOD.

